First, StepUp is started with 9 workers to complete the steps in the RepRep publication template from scratch.
After the build has completed, the file generate.py is modified, whose output is used in a matplotlib plot created by plot.py, whose output is included in a LaTeX document, etc.
Stepup sees the changes. As soon as the user presses r, StepUp executes the necessary steps to rebuild all artifacts that are (indirectly) affected by the change in generate.py.